I think I already know the answer, but want to run it by the board and all it's collective wisdom.

My son called me this AM from inside his pickup in downtown New Orleans. (It was 30 deg. F outside at the time.) I didn't get the greatest of details fromhim but I think I got the gist:

-Apparently his gas pedal would not come back up after he started the truck, and the throttle was fully open by the revving he described.-He also mentioned the cable was slack when he manually lifted up the pedal with his hand. (is this possible?)-I'm not clear on how long he let the engine run at such high RPMs, but I think he may have started and restarted it a few times.Anyway, while on the phone with him, he said it "fixed itself" and all was normal now. I stayed on the phone with him while he was driving to work and allwas good.

My guess, and hope, is that the throttle linkage(s) just need some oiling and that the cold weather made things "sticky" for a bit. I would like to addressthis problem so it doesn't happen again; or in a more dangerous circumstance.

I'm going to advise him to put a little engine oil on all the moving parts he sees at the throttle linkage, including any exposed accelerator cable parts, unlessyou folks give me reason to think otherwise.

Since I'm inexperienced in most things mechanical, your insights are of great value concerning all things Isuzu.

I'm not sure if you will find this helpful or not. My truck does not have a manual choke. For cold starts, I pump the gas pedal twice then start the truck. Then it's a matter of waiting a few minutes as the engine warms and increases idle speed. Once the engine evens out, I tap the pedal and it bumps the idle back down. The first time someone experiences this (my roommate wanted to borrow the truck and caming running inside in a panic) it can be loud and scary as the engine revs up.

By the way, can your son please send the cold weather back? It's looking like May up here.

With him revving out a cold engine he may end up calling you again for other problems in the future. Best advise him to stop that.

Anyhow is is most probable that the throttle plate got stuck open in the housing.

There is a throttle return spring that pulls back on the throttle cable and that is what returns it to rest position. If the plate is stuck, then the linkage won't return meaning the accelerator pedal stays down. The cable is thin and flexes so you can push back against it which is why he was able to lift it by hand.

It probably fixed itself either by the tension of the spring finally pulling it back or he pressed down on the throttle again and that shifted the throttle plate, freeing it.

Possible that the linkage nut needs looking at as it sounds like the plate is moving around. I don't think there is anything motor oil will help in this situation, Just some adjustment needed, or maybe he was pressing down on it with all his might? The motor oil might just attract more dirt and grit.